The present invention relates to an image processing system, projector, program, information storage medium and image processing method which can correct image signals so that images projected by a plurality of image projection means are overlapped at a projection target area.
To secure the brightness of an image and to improve the dynamic range and color in the image, there has been realized an image display system comprising a plurality of projectors for projecting images so that they could be overlapped one another at a projection target area such as a screen. Such a projection of images is also called “stack projection”.
In such an image display, however, the projection angles of the projectors are different from one another and consequently a distortion will occur in an image consisting of the projected and overlapped images. If a single projector is used to project an image and even when a distortion occurs therein, it is only required to regulate the distortion. If a plurality of projectors are used, however, it is required to regulate the projected mages to their proper display positions in addition to the regulation of the image distortions.
For such a reason, technical knowledge and great labor are required to perform the stack projection.
To facilitate the alignment in such overlapped images, for example, Japanese Patent Application Laid-Open No. 8-168039 has proposed a projection type display system which is operative to synthesize inspection for inspection patterns and video signals or to intermittently generate inspection signals, to project an image onto a screen, to detect the position of an inspection pattern image in the image projected onto the screen, to control the projecting position so that there is no misalignment.
In Japanese Patent Application Laid-Open No. 8-168039, however, it is presumed that a projected image is of rectangular shape. The projection type display system merely changes an optical projection axis in a hardware manner by detecting the position of the inspection pattern image and determining the amount of misalignment.
For such a reason, it is difficult that the technique of Japanese Patent Application Laid-Open No. 8-168039 causes the projection type display system to properly align the image positions under such a condition that a distortion of an image occurs as when a plurality of projectors are used or when a projector is not opposed directly to a screen.
In addition, Japanese Patent Application Laid-Open No. 8-168039 does not describe at all the fact that the projection type display system will change the color of a composite image by superimposing images.